Exhibit A Underlying SMBS Securities Trust Asset Group Issuer Series Class Issue Date CUSIP Number Interest Rate Interest Type(1) Final Distribution Date Principal Type(1) Original Principal or Notional Balance of Class Underlying Certificate Factor(2) Principal or Notional Balance in the Trust Percentage of Class in Trust Approximate Weighted or Notional Average Coupon of Mortgage Loans Approximate Weighted Average Remaining Term to Maturity of Mortgage Loans (in months) Approximate Weighted Average Loan Age of Mortgage Loans (in months) Ginnie Mae I or II 1 Ginnie Mae   SMBS 01 1 7/30/2004   37610VAA3 0.0% PO July 2034 PT   $2,200,000,000   0.86731816   $265,093,500    13.8930615455% 5.900% 344 14 II 1 Ginnie Mae   SMBS 01 2 7/30/2004   37610VAB1 5.5% IO July 2034 NTL(PT)    $2,200,000,000    0.86731816    $240,994,091   12.6300559545% 5.900% 344 14 II (1)  As defined under "Class Types" in Appendix I to the Base Offering Circular. (2)  Underlying Certificate Factors are as of June 2005. A-1